Minecraft version: 1.20.1

Modloader: Fabric

Mod version: [1.20.1] SW-1.2.4 fabric

There's a problem where when i use persistent data with KubeJS the data are saved in soulsweapons_data player tag.
Is there a way to disable it and use Kubejs persistent data?

Because when I die, the data is deleted

No you can't delete the soulsweapons_data nbt tag, it is used for many things such as parrying, posture and recording the amount of summons the player has. Not sure why you need it removed, haven't used KubeJS before so not sure what the conflict is. The fact that the data is removed when the player dies is both fine and intentional.